No service after iOS 12
Hello,
My network stopped working all of sudden and I realised it was just after the newest update. I contacted my carieer - my sim card plan (Virgin Mobile), everything related to it has been checked and it's fully working. I checked the sim on my friend's iphone just to be sure and it was working as well, so surely it's the phone.
The network comes back sometimes for little time, working, and then stops and this appears again (see pic below). The info pops out that the service failed and that iphone is unable to make or receive calls. I did everything - reset network settings, reset the whole content and settings too, restarted, restored, everything. I went to the apple store, the did the same, besides the fact that after reseting it in the store, they weren't able to activate the iphone, so it was completely useless as I couldn't go through the installation. Eventually I managed to activate it back at home, when network came back for just a bit. Other thing is that I bought this Iphone unlocked in US about three years ago, never ever had a problem with it, switched multiple SIM cards, everything always worked until latest update.
So my iphone says it requires an update, yet the iphone is up to date. Thoughts please?
iPhone 7, iOS 12